Condensate and Main Feed Flashcards
LCO 3.7.3 “Main Feedwater Regulating Valves (MFRVs) and MFRV Bypass Valves” requirements
2 MFRVs and 2 MFRV Bypass Valves shall be operable
LCO 3.7.3 “Main Feedwater Regulating Valves (MFRVs) and MFRV Bypass Valves” applicability
Modes 1-3, except when both MFRVs and both MFRV Bypass Valves are either closed and de-activated, or isolated by closed manually actuated valves
LCO 3.7.6 “Condensate Storage and Supply” requirements
The combined usable volume of the Condensate Storage Tank (CST) and Primary Makeup Storage Tank (T-81) shall be >= 100,000 gallons
T-2 > 71%
T-81 > 83%
LCO 3.7.6 “Condensate Storage and Supply” applicability
Modes 1-3
Mode 4 when steam generator is relied upon for heat removal
What level is the hotwell normally maintained at?
66-71%
How is hotwell level normally maintained?
- Normal 3” makeup valve auto opens at 66%
- 4” reject CV auto opens at 76% and rejects water to T-2
What is the precaution based on control/indication of hotwell 4” reject valve?
No indication or control in the control room, so if the valve fails open, hotwell level will lower, and damage could occur to the condensate pumps
What are the power supplies for the condensate pumps?
P-2A - ‘A’ Bus
P-2B - ‘B’ Bus
What is the design flow/pressure of the condensate pumps?
9250 gpm @ 500 psi
What is the power limit with only 1 condensate pump running?
30%
What is the function of the condensate recirc CV?
- Maintains minimum flow through air ejector condenser (5200 gpm) and gland seal condenser (1600 gpm) @ 6800 gpm
- Gives condensate pumps a flow path on plant startups and shutdowns
How does the condensate recirc CV fail on a loss of air?
Closed
What causes the condensate recirc CV to auto open?
Plant trip or 25% power and lowering
When is the condensate recirc CV closed?
Approximately 35-40% power and rising
What are the reset permissives for the MFPs?
- Suction valve open
- Condenser vacuum > 15” Hg
- T&T valve closed
What are the MFP trips?
- Thrust bearing
- LSPT (2/3 logic 250 psig for 3 seconds)
- Low bearing oil pressure (9 psig)
- Low governor oil pressure (25 psig)
- Overspeed (5500 rpm)
What MFP speed is maintained by the MFP governor?
3250-5250 rpm
What is the interlock between the MFP recirc CV and T&T valve?
- If both T&T valves are closed, MFP recirc CV is closed.
- If either T&T valve is open, MFP recirc CV will be able to modulate open based on MFP suction flow (3000 gpm = full open, 6000 gpm = full closed)
What is the purpose of the MFP recirc CVs?
Provide minimum flow protection for the MFPs
What are the power supplies for the MFP recirc CVs?
P-1A recirc CV - Y-10
P-1B recirc CV - Y-20
How do the MFP recirc CVs fail on a loss of air or preferred AC?
Open
Approximately what power levels are the MFP recirc CVs used?
Throttled open from 0-45% power